(1 – 4 / 9) / (1 / 3 – 1 / 4)

(1-4/9):(1/3-1/4)=6 2/3 1) 9/9-4/9=5/9 2) 1/3-1/4=4/12-3/12=1/12 3) 5/9:1/12=5/9·12/1=20/3=6 2/3